Transmission apparatus, transmission method, encoding apparatus, encoding method, reception apparatus, and reception method

ABSTRACT

A transmission apparatus includes a transmission unit. The transmission unit transmits a packet including divided image data as payload data, the divided image data being obtained by dividing image data having a predetermined frame frequency into a predetermined number of frames, the image data having the predetermined frame frequency being subjected to mixing processing for each frame, image data of a previous frame and/or a subsequent frame being selectively used in the mixing processing, and further transmits metadata including information regarding the mixing processing in association with image data of each frame.

BACKGROUND

The present technology relates to a transmission apparatus, atransmission method, an encoding apparatus, an encoding method, areception apparatus, and a reception method, and more particularly, to atransmission apparatus that handles image data on which mixingprocessing is performed, and the like.

In a case where a receiver, which performs decoding at a frame rate atwhich broadcasting has been performed from the past, receivesbroadcasting at a high frame rate, partial decoding of a stream impairscontinuity of motions and degrades the quality of moving images. It issaid that the degradation of the quality of moving images is mainlycaused by strobing. The stroking occurs when the retinal projection ofhuman eyes with respect to a quick motion becomes intermittent becausetime continuity between pictures partially decoded becomes coarse.

In order to reduce the degradation of the quality of moving images dueto the strobing, the present applicant has been proposed the technologyof performing pixel mixing between a picture and a previous orsubsequent picture thereof in a frame period to be a reference (see WO2015/076277). In this case, even if the receiver in the related artperforms time subsampling, it is reflected in time sampling in which anelement that has moved is partially decoded, thus reducing thedegradation of the quality of moving images due to the strobing.

SUMMARY

It is desirable for a reception side to favorably handle image data onwhich mixing processing is performed, for example, at transmission ofmaterials of the image data.

A concept of the present technology resides in a transmission apparatusincluding a transmission unit that transmits a packet including dividedimage data as payload data, the divided image data being obtained bydividing image data having a predetermined frame frequency into apredetermined number of frames, the image data having the predeterminedframe frequency being subjected to mixing processing for each frame,image data of a previous frame and/or a subsequent frame beingselectively used in the mixing processing, and further transmitsmetadata including information regarding the mixing processing inassociation with image data of each frame.

In the present technology, by the transmission unit, a packet includingdivided image data as payload data is transmitted, the divided imagedata being obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames. Here, the image datahaving the predetermined frame frequency is subjected to mixingprocessing for each frame, image data of a previous frame and/or asubsequent frame being selectively used in the mixing processing. Forexample, the packet may conform to a format prescribed by a standardregarding video signal transmission using an internet protocol (IP)network. In this case, for example, the standard may be SMPTE ST2022-6or SMPTE ST2110-20. For example, the transmission apparatus may furtherinclude a mixing processing unit that performs the mixing processing.

By the transmission unit, metadata including information regarding themixing processing may further be transmitted in association with imagedata of each frame. For example, the mixing processing may include apredetermined number of stages of the mixing processing. Further, forexample, the information regarding the mixing processing may include anyone of information indicating whether image data of a correspondingframe is subjected to mixing processing or not, information of a camerashutter speed at capturing, information of a frame rate of a mixingprocessing target picture, information of a frame rate obtained afterthe mixing processing, information indicating a mixing processing targetpicture, and information indicating a filter operation coefficient ratioat mixing.

For example, the transmission unit may insert the metadata into apayload header of the packet including at least a top of the image dataof each frame and transmit the metadata. Further, for example, thetransmission unit may transmit the metadata in a metadata-dedicatedpacket associated with the packet including the image data of eachframe.

As described above, in the present technology, a packet includingdivided image data as payload data, the divided image data beingobtained by dividing image data having a predetermined frame frequencyinto a predetermined number of frames, is transmitted, and metadataincluding information regarding the mixing processing is alsotransmitted in association with image data of each frame. Thus, it ispossible for a reception side to favorably handle image data on whichmixing processing is performed, for example, at transmission ofmaterials of the image data.

Further, another concept of the present technology resides in anencoding apparatus including: a reception unit that receives a packetincluding divided image data as payload data, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames, the image data havingthe predetermined frame frequency being subjected to mixing processingfor each frame, image data of a previous frame and/or a subsequent framebeing selectively used in the mixing processing, and further receivesmetadata including information regarding the mixing processing, themetadata being associated with image data of each frame, the informationregarding the mixing processing including information indicating whetherimage data of a corresponding frame is subjected to mixing processing ornot; and an encoding unit that, on the basis of the informationregarding the mixing processing, encodes, among the image data havingthe predetermined frame frequency, image data of a frame subjected tothe mixing processing as image data of a base layer and encodes, amongthe image data having the predetermined frame frequency, image data of aframe not subjected to the mixing processing as image data of anenhanced layer.

In the present technology, by the reception unit, a packet includingdivided image data as payload data is received, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames. Here, the image datahaving the predetermined frame frequency is subjected to mixingprocessing for each frame, image data of a previous frame and/or asubsequent frame being selectively used in the mixing processing.Further, metadata including information regarding the mixing processingis further received, the metadata being associated with image data ofeach frame. Here, the information regarding the mixing processingincludes information indicating whether image data of a correspondingframe is subjected to mixing processing or not.

By the encoding unit, among the image data having the predeterminedframe frequency, image data of a frame subjected to the mixingprocessing is encoded as image data of a base layer, and among the imagedata having the predetermined frame frequency, image data of a frame notsubjected to the mixing processing is encoded as image data of anenhanced layer, on the basis of the information regarding the mixingprocessing.

As described above, in the present technology, the image data having thepredetermined frame frequency subjected to the mixing processing isencoded on the basis of the information regarding the mixing processing(including information indicating whether image data of a correspondingframe is subjected to mixing processing or not). Thus, it becomespossible to easily and suitably encoding, among the image data havingthe predetermined frame frequency, image data of a frame subjected tothe mixing processing as image data of a base layer and encoding, amongthe image data having the predetermined frame frequency, image data of aframe not subjected to the mixing processing as image data of anenhanced layer.

Further, another concept of the present technology resides in areception apparatus including: a reception unit that receives a packetincluding divided image data as payload data, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames, the image data havingthe predetermined frame frequency being subjected to mixing processingfor each frame, image data of a previous frame and/or a subsequent framebeing selectively used in the mixing processing, and further receivesmetadata including information regarding the mixing processing, themetadata being associated with image data of each frame; and aprocessing unit that performs inverse mixing processing on the imagedata having the predetermined frame frequency on the basis of theinformation regarding the mixing processing, and acquires image data fordisplay.

In the present technology, by the reception unit, a packet includingdivided image data as payload data is received, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames. Here, the image datahaving the predetermined frame frequency is subjected to mixingprocessing for each frame, image data of a previous frame and/or asubsequent frame being selectively used in the mixing processing.Further, metadata including information regarding the mixing processingis further received, the metadata being associated with image data ofeach frame.

By the processing unit, inverse mixing processing is performed on theimage data having the predetermined frame frequency on the basis of theinformation regarding the mixing processing, and image data for displayis acquired.

As described above, in the present technology, inverse mixing processingis performed on the image data having the predetermined frame frequency,which is subjected to the mixing processing, on the basis of theinformation regarding the mixing processing, and image data for displayis acquired. Thus, it is possible to easily and suitably perform inversemixing processing and acquire image data for display.

These and other objects, features and advantages of the presentdisclosure will become more apparent in light of the following detaileddescription of best mode embodiments thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are diagrams respectively showing a broadcasting flowand an example of a system configuration corresponding toimaging/production and delivery steps;

FIG. 2 is a diagram showing a configuration example of atransmission/reception system including a transmission side forimaging/production/delivery and a reception side for reception/display;

FIG. 3 is a diagram showing another configuration example of thetransmission side;

FIG. 4 is a diagram showing a configuration example of a productiondevice that performs processing check;

FIG. 5 is a diagram for describing layer sorting in hierarchical codingby an encoder;

FIGS. 6A and 6B are diagrams for describing the layer sorting in thehierarchical coding by the encoder;

FIGS. 7A and 7B are diagrams for describing a shutter rate at imaging;

FIG. 8 is a diagram showing an example of a correspondence relationshipbetween a shutter speed (1/sec), a transmission frame rate (fps), and ashutter angle (degree);

FIG. 9 is a diagram for describing an example of mixing processing;

FIG. 10 is a diagram for describing another example of the mixingprocessing;

FIG. 11 is a diagram for describing still another example of the mixingprocessing;

FIG. 12 is a diagram showing an example of a packet;

FIG. 13 is a diagram showing a structural example of an RTP header;

FIG. 14 is a diagram showing the contents of main information in thestructural example of the RTP header;

FIG. 15 is a diagram showing a structural example of a payload header;

FIG. 16 is a diagram showing the contents of main information in thestructure of the payload header;

FIG. 17 is a diagram showing a structural example of “shutter_blending ()”;

FIG. 18 is a diagram showing the contents of main information in astructural example of “shutter_blending ( )”;

FIGS. 19A and 19B are each a diagram for describing a specific exampleof metadata;

FIGS. 20A and 20B are each a diagram for describing a specific exampleof metadata;

FIG. 21 is a diagram for describing a specific example of metadata;

FIG. 22 is a diagram showing an example in which pictures aretransmitted in a plurality of packets (media packets) through RTPtransmission;

FIG. 23 is a diagram showing another example in which pictures aretransmitted in a plurality of packets (media packets) through RTPtransmission;

FIG. 24 is a diagram showing a structural example of a payload header;and

FIG. 25 is a diagram showing a structural example of a payload headerand a payload of a metadata packet.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, a mode for implementing the present disclosure(hereinafter, referred to as embodiment) will be described. Note thatdescription will be given in the following order.

1. Embodiment

2. Modified example

1. Embodiment

Broadcasting Flow

FIG. 1A shows a broadcasting flow. The broadcasting flow includes animaging/production step of acquiring image data of a material video, adelivery step of transmitting the image data of the material video, anda reception/display step of receiving the image data of the materialvideo and performing image displaying.

FIG. 1B shows an example of a system configuration corresponding to theimaging/production step and the delivery step. For example, image datahaving a predetermined frame frequency of a material video captured byimaging apparatuses (hereinafter, cameras) in a stadium is transmittedto an outside broadcasting van. Further, for example, image data havinga predetermined frame frequency of a material video captured by a cameraof a drone is transmitted to the outside broadcasting van. Further, forexample, image data having a predetermined frequency is transmitted as amaterial video from a video material server to the outside broadcastingvan.

Further, the image data of the material video that is obtained afterediting in the outside broadcasting van is transmitted to a broadcastingcenter via a relay station. Further, image data having a predeterminedframe frequency of a material video captured by a camera in a studio istransmitted to the broadcasting center. The image data having thepredetermined frame frequency of the material video is then encoded andtransmitted from the broadcasting center via broadcast wave.

The above-mentioned image data having the predetermined frame frequencyof each material video is a transmission target according to society ofmotion picture and television engineers (SMPTE) standard. In this case,the image data having the predetermined frame frequency is divided intoa predetermined number of frames, and a packet including the dividedimage data obtained thereby is transmitted as payload data. The packetconforms to the format prescribed by a standard regarding video signaltransmission using an Internet protocol (IP) network. In this case, thevideo signal is, for example, a signal of a material video of a program.

In this embodiment, mixing processing in which image data of a previousframe and/or a subsequent frame is selectively used is performed foreach frame on the image data having the predetermined frame frequency ofthe material video. The mixing processing is performed in order tomitigate degradation of the quality of moving images due to strobing ina receiver that creates a display image by partial decoding.

The mixing processing is performed by a mixing processing unit, e.g., apreprocessor (PreProc), included in an imaging apparatus that capturesmaterial videos, such as a camera of a drone, a camera of a stadium, ora camera of a studio. Alternatively, the mixing processing is performedby a preprocessor included in an apparatus that receives a materialvideo captured by the imaging apparatus, such as a drone, a videomaterial server, an outside broadcasting van, or a relay station. Themixing processing is performed not only in one stage but also in twostages, three stages, . . . Note that all of the camera of the drone (ordrone), the camera of the stadium, the video material server, theoutside broadcasting van, the relay station, and the camera of thestudio do not need to include a preprocessor, but it is assumed that themixing processing is performed on at least the image data having thepredetermined frame frequency of the material video, which istransmitted to the broadcasting center.

In a case where the image data having the predetermined frame frequency,on which the mixing processing is performed, is to be transmitted to thenext stage, metadata including information regarding the mixingprocessing is associated with image data of each frame and thentransmitted. The information regarding mixing processing includesinformation indicating whether the mixing processing is performed onimage data of a corresponding frame or not, and the like.

Transmission/Reception System

FIG. 2 shows a configuration example of a transmission/reception system10 including a transmission side for imaging/production/delivery and areception side for reception/display. The transmission side includes acamera 101 and a broadcasting center 102. The camera 101 corresponds tothe camera of the drone, the camera of the stadium, or the camera of thestudio in FIG. 1B, or the like.

The camera 101 captures image data having a predetermined framefrequency as a material video. A. preprocessor 101 a of the camera 101performs mixing processing on the image data having the predeterminedframe frequency for each frame. In the mixing processing, image data ofa previous frame and/or a subsequent frame is selectively used. In thiscase, in the preprocessor 101 a, down-conversion processing for a framefrequency is also performed as necessary.

A transmission unit (not shown) of the camera 101 transmits packets tothe broadcasting center 102, the packets each including divided imagedata as payload data. The divided image data is obtained by dividing theimage data having the predetermined frame frequency, on which the mixingprocessing described above is performed, into a predetermined number offrames. Further, the transmission unit (not shown) of the camera 101transmits metadata A to the broadcasting center 102 in association withimage data of each frame. The metadata A includes the informationregarding the mixing processing.

A reception unit (not shown) of the broadcasting center 102 receives thepackets transmitted from the camera 101, and the broadcasting center 102acquires the image data having the predetermined frame frequency, i.e.,a material video on which the mixing processing is performed. Further,the reception unit receives the metadata A transmitted from the camera101.

A high level parser (HLP) unit 102 a of the broadcasting center 102interprets the metadata A associated with image data of each frame. Onthe basis of this interpretation, an encoder 102 b of the broadcastingcenter 102 performs hierarchical coding using, for example, highefficiency video coding (HEVC) on the image data having thepredetermined frame frequency, i.e., a material video on which themixing processing is performed. The broadcasting center 102 thenacquires a base stream STb, a first enhanced stream STe1, and a secondenhanced stream STe2.

In this case, for example, the encoder 102 b encodes, among the imagedata having the predetermined frame frequency, image data of a framesubjected to the mixing processing as image data of a base layer andencodes, among the image data having the predetermined frame frequency,image data of a frame not subjected to the mixing processing as imagedata of an enhanced layer.

A transmission unit (not shown) of the broadcasting center 102 transmitsthe base stream STb, the first enhanced stream STe1, and the secondenhanced stream STe2. In this case, metadata including the informationregarding the mixing processing is also transmitted in association withimage data of each frame. For example, the transmission is performed byinserting an SEI message, which is newly defined and includes themetadata, into a “SEIs” portion of an access unit (AU) of each picture(frame).

Note that the example in the figure shows that two enhanced streams ofthe first enhanced stream STe1 and the second enhanced stream STe2 otherthan the base stream STb are transmitted, but a case of one enhancedstream or three or more enhanced streams is also conceived.

The reception side includes, for example, a set-top box 211 and adisplay 212. A reception unit (not shown) of the set-top box 211receives the base stream STb, the first enhanced stream STe1, the secondenhanced stream STe2, and the metadata including the informationregarding the mixing processing associated with image data of eachstream.

An HLP unit 211 a of the set-top box 211 interprets the metadatatransmitted in association with image data of each frame. Further, adecoder 211 b of the set-top box 211 performs decoding processing on thebase stream STb, the first enhanced stream STe1, and the second enhancedstream STe2 and acquires, for example, image data of 240 Hz.

A transmission unit (not shown) of the set-top box 211 transmits theimage data of 240 Hz and the metadata corresponding to each frame to thedisplay 212 by using, for example, a digital interface such as ahigh-definition multimedia interface (HDMI).

A reception unit (not shown) of the display 212 receives the image dataof 240 Hz and the metadata corresponding to each frame, which aretransmitted from the set-top box 211. On the basis of the metadata, apostprocessor 212 a of the display 212 performs inverse mixingprocessing on the image data of the base layer on which the mixingprocessing is performed, among the image data of 240 Hz, and acquiresthe image data before mixing.

Further, the display 212 uses the image data of 240 Hz obtained in thepostprocessor 212 a as image data for display, without change or afterframe interpolation processing is performed in a motion compensatedframe insertion (MCFI) unit 212 b to increase the frame rate.

Further, the reception side includes, for example, a set-top box 221 anda display 222. A reception unit (not shown) of the set-top box 221receives the base stream STb, the first enhanced stream STe1, and themetadata including the information regarding the mixing processingassociated with image data of each stream.

An HIP unit 221 a of the set-top box 221 interprets the metadatatransmitted in association with image data of each frame. Further, adecoder 221 b of the set-top box 221 performs decoding processing on thebase stream STb and the first enhanced stream STe1 and acquires, forexample, image data of 120 Hz.

A transmission unit (not shown) of the set-top box 221 transmits theimage data of 120 Hz and the metadata corresponding to each frame to thedisplay 222 by using, for example, a digital interface such as an HDMI.

A reception unit (not shown) of the display 222 receives the image dataof 120 Hz and the metadata corresponding to each frame, which aretransmitted from the set-top box 221. On the basis of the metadata, apostprocessor 222 a of the display 222 performs inverse mixingprocessing on the image data of the base layer on which the mixingprocessing is performed, among the image data of 120 Hz, and acquiresthe image data before mixing.

Further, the display 222 uses the image data of 120 Hz obtained in thepostprocessor 222 a as image data for display, without change or afterframe interpolation processing is performed in an MCFI unit 222 b toincrease the frame rate.

Further, the reception side includes, for example, a set-top box 231 anda display 232. A reception unit (not shown) of the set-top box 231receives the base stream STb. A decoder 231 a of the set-top box 231performs decoding processing on the base stream STb and acquires, forexample, image data of 60 Hz. A transmission unit (not shown) of theset-top box 231 transmits the image data of 60 Hz to the display 232 byusing, for example, a digital interface such as an HDMI.

A reception unit (not shown) of the display 232 receives the image dataof 60 Hz transmitted from the set-top box 231. The display 232 uses thereceived image data of 60 Hz as image data for display, without changeor after frame interpolation processing is performed in an MCFI unit 232a to increase the frame rate.

Note that the example in the figure shows three systems on the receptionside, but the present technology is not limited thereto. For example,the number of systems may change depending on the number of enhancedstreams.

FIG. 3 shows another configuration example of the transmission side. InFIG. 3, portions corresponding to those in FIG. 2 are denoted byidentical reference symbols. The transmission side includes a camera101, a production device 103, and a broadcasting center 102. The camera101 corresponds to, for example, the camera of a drone or the camera ofa stadium in FIG. 1B. The production device 103 corresponds to, forexample, the outside broadcasting van or the relay station in FIG. 1B.

The camera 101 captures image data having a predetermined framefrequency as a material video, and a preprocessor 101 a performs mixingprocessing on the image data having the predetermined frame frequencyfor each frame. In the mixing processing, image data of a previous frameand/or a subsequent frame is selectively used. In this case, in thepreprocessor 101 a, down-conversion processing for a frame frequency isalso performed as necessary.

A transmission unit (not shown) of the camera 101 transmits packets tothe production device 103, the packets each including divided image dataas payload data. The divided image data is obtained by dividing theimage data having the predetermined frame frequency, on which the mixingprocessing described above is performed, into a predetermined number offrames. Further, the transmission unit (not shown) of the camera 101transmits metadata A to the production device 103 in association withimage data of each frame. The metadata A includes the informationregarding the mixing processing.

A reception unit (not shown) of the production device 103 receives thepackets transmitted from the camera 101, and the production device 103acquires the image data having the predetermined frame frequency, i.e.,a material video on which the mixing processing is performed. Further,the reception unit receives the metadata A transmitted from the camera101.

An HLP unit 103 a of the production device 103 interprets the metadata Aassociated with image data of each frame. On the basis of thisinterpretation, a preprocessor 103 b performs mixing processing on theimage data having the predetermined frame frequency for each frame. Inthe mixing processing, image data of a previous frame and/or asubsequent frame is selectively used. The preprocessor 103 b thenacquires image data having a predetermined frame frequency on whichmulti-stage, here, two-stage mixing processing is performed. In thiscase, in the preprocessor 103 b, down-conversion processing for a framefrequency is also performed as necessary.

A transmission unit (not shown) of the production device 103 transmitspackets to the broadcasting center 102, the packets each includingdivided image data as payload data. The divided image data is obtainedby dividing the image data having the predetermined frame frequency, onwhich the mixing processing described above is performed, into apredetermined number of frames. Further, the transmission unit (notshown) of the production device 103 transmits metadata B to thebroadcasting center 102 in association with image data of each frame.The metadata B includes information regarding the multi-stage mixingprocessing.

A reception unit (not shown) of the broadcasting center 102 receives thepackets transmitted from the production device 103, and the broadcastingcenter 102 acquires the image data having the predetermined framefrequency, i.e., a material video on which the mixing processing isperformed. Further, the reception unit receives the metadata Btransmitted from the production device 103.

A HLP unit 102 a of the broadcasting center 102 interprets the metadataB associated with image data of each frame. On the basis of thisinterpretation, an encoder 102 b of the broadcasting center 102 performshierarchical coding using, for example, high efficiency video coding(HEVC) on the image data having the predetermined frame frequency, i.e.,a material video on which the mixing processing is performed. Thebroadcasting center 102 then acquires a base stream STb, a firstenhanced stream STe1, and a second enhanced stream STe2.

In this case, the encoder 102 b encodes, among the image data having thepredetermined frame frequency, image data of a frame subjected to themixing processing as image data of a base layer and encodes, among theimage data having the predetermined frame frequency, image data of aframe not subjected to the mixing processing as image data of anenhanced layer.

A transmission unit (not shown) of the broadcasting center 102 transmitsthe base stream STb, the first enhanced stream STe1, and the secondenhanced stream STe2. In this case, metadata including the informationregarding the mixing processing is also transmitted in association withimage data of each frame. For example, the transmission is performed byinserting an SEI message, which is newly defined and includes themetadata, into a “SEIs” portion of an access unit (AU) of each picture(frame).

Note that the example in the figure shows that two enhanced streams ofthe first enhanced stream STe1 and the second enhanced stream STe2 otherthan the base stream STb are transmitted, but a case of one enhancedstream or three or more enhanced streams is also conceived.

Processing Check

Although not described above, it is also conceived that, in theproduction device 103, a user determines whether to perform the mixingprocessing in the preprocessor 103 b on the image data transmitted fromthe former stage, here, the camera 101, after viewing the image qualityof the image data on which the mixing processing is performed in thepreprocessor 103 b.

At that time, there is also a case where the determination is made onthe basis of the image quality of a display image of image data, whichis obtained by performing inverse mixing processing in the postprocessorafter passing through the encoder/decoder, as in actual broadcasting.Further, at that time, there is also a case where the determination ismade on the basis of the image quality of a display image of image dataon which mixing processing is performed after passing through theencoder/decoder, as in actual broadcasting. Additionally, at that time,there is also a case where the determination is made on the basis of theimage quality of a display image of image data on which uncompressedmixing processing is performed without passing through theencoder/decoder.

FIG. 4 shows a configuration example of the production device 103 insuch a case. The production device 103 includes, in addition to the HLPunit 103 a and the preprocessor 103 b, an encoder 103 c, a decoder 103d, a postprocessor 103 e, and a production monitor 103 f.

The image data having the predetermined frequency obtained by performingthe mixing processing in the preprocessor 103 b is transmitted to theproduction monitor 103 f as first image data. Further, the image datahaving the predetermined frequency obtained by performing the mixingprocessing in the preprocessor 103 b is transmitted to the productionmonitor 103 f as second image data after encoding by the encoder 103 cand decoding by the decoder 103 d.

Further, the image data having the predetermined frequency obtained fromthe decoder 103 d is transmitted to the production monitor 103 f asthird image data after inverse mixing processing is performed in thepostprocessor 103 e. The inverse mixing processing performed in thepostprocessor 103 e is performed on the basis of the metadata B outputfrom the preprocessor 103 b, though not shown in the figure.

In this configuration example, the user can determine whether the mixingprocessing is to be performed or not in the preprocessor 103 b, byselectively switching the first image data, the second image data, orthe third image data and viewing respective display images on theproduction monitor 103 f. Note that, in a case where the mixingprocessing is not performed in the preprocessor 103 b, the image dataand the metadata B transmitted from the production device 103 to asubsequent stage, here, the broadcasting center 102, are the same as theimage data and the metadata A transmitted from the camera 101 to theproduction device 103.

Layer Sorting in Hierarchical Coding by Encoder

As described above, for example, the encoder 102 b encodes, among theimage data having the predetermined frame frequency, image data of aframe subjected to the mixing processing as image data. of a base layer,and encodes, among the image data having the predetermined framefrequency, image data of a frame not subjected to the mixing processingas image data of an enhanced layer.

The metadata including the information regarding the mixing processingassociated with the image data of each frame, which is transmittedtogether with the image data having the predetermined frame frequency onwhich the mixing processing is performed by the encoder 102 b, includes“Blending_flag” that is information indicating whether the mixingprocessing is performed on image data of a corresponding frame or not.As shown in FIG. 5, layer sorting processing in the encoder 102 b isperformed on the basis of “Blending_flag”.

In this case, as shown in FIG. 6A, the encoder 102 b switchesaccumulation to a reference buffer/referenced buffer of the encoder 102b on the basis of “Blending_flag” of a picture (frame) to be input. If“Blending_flag=1”, a picture is accumulated in a referenced buffer inencoding. If “Blending_flag=0”, a picture is accumulated in a referencebuffer in encoding.

As shown in FIG. 6B, pictures of the base layer in the referenced buffercan be referenced by pictures of the enhanced layer in the referencebuffer, and the pictures of the enhanced layer in the reference bufferare not referenced by other pictures.

Shutter Rate at Imaging

A shutter rate at imaging will be described. FIG. 7A shows image datacaptured at a shutter speed of 1/240 sec at a frame frequency of 240 Hz(240 fps). The image data has a configuration in which four framesections of P1, P2, P3, and P4 are repeated.

In this case, the shutter is open in all the time of the frame intervalof 240 Hz. Thus, a shutter angle (shutter rate) α is 360 degrees (100%)as expressed by the following mathematical expression (1).

α=360*240/240=360   (1)

FIG. 7B shows image data captured at a shutter speed of 1/300 sec at aframe frequency of 240 Hz (240 fps). The image data has a configurationin which four frame sections of P1, P2, P3, and P4 are repeated.

In this case, a period during which the shutter is open with respect tothe frame interval of 240 Hz is short, i.e., 1/300 sec. Thus, a shutterangle (shutter rate) α is 288 degrees (80%) as expressed by thefollowing mathematical expression (2).

α=360*240/300=288   (2)

FIG. 8 shows an example of a correspondence relationship between ashutter speed (1/sec), a transmission frame rate (fps), and a shutterangle (degree). In general, the shutter angle (degree) is calculated bythe following mathematical expression (3).

Shutter angle (degree)=360*(transmission frame rate)*(shutter speed)  (3)

Mixing Processing

As described above, the mixing processing is performed in order tomitigate degradation of the quality of moving images due to strobing ina receiver that creates a display image by partial decoding. Image dataon which the mixing processing is not performed is image data in anincompatible mode, and image data on which the mixing processing isperformed is image data in a low-frame-rate compatible mode.

With reference to FIG. 9, an example of the mixing processing will bedescribed. In FIG. 9, (a) shows image data in an incompatible mode onwhich the mixing processing is not performed, the image data having abasic format. This image data is image data obtained when imaging isperformed at a frame frequency of 240 Hz (240 fps) and at a shutterspeed of 1/240 sec. The image data has a configuration in which fourframe (picture) sections of P1, P2, P3, and P4 are repeated. A shutterangle (shutter rate) α of each frame in this case 360 degrees (100%)(see FIG. 7A).

In FIG. 9, (b) shows image data of 240 Hz in a low-frame-rate compatiblemode on which the mixing processing is performed. The image data has aconfiguration in which four frame sections of Q1, Q2, Q3, and Q4 arerepeated. The image data of each of the frames of Q1, Q2, and Q4 is thesame as image data of each of the frames of P1, P2, and P4,respectively. A shutter angle (shutter rate) α of each of the frames ofQ1, Q2, and Q4 is 360 degrees (100%).

The image data of the frame of Q3 is mixed image data t (P2, P3, P4)obtained by performing filter operation on the image data of the framesof P2, P3, and P4. In this case, the image data of the frame of Q3includes pixel elements of the three frames of P2, P3, and P4 mixedusing the filter operation. Since a shutter angle (shutter rate) β ofthe frame of Q3 reflects the pixel elements of the three frames in oneframe of 240 Hz, as expressed by the following mathematical expression(4), the shutter angle (shutter rate) β of the frame of Q3 is 360*3degrees (300%).

β=360*240/240*3=360*3   (4)

In FIG. 9, (c) shows image data obtained when the reception sideextracts the image data of the frame of Q3 on which the mixingprocessing is performed, and then displays such image data at 60 Hz.Image data of a frame of R3 is for displaying the image data of theframe of Q3 at time intervals of 60 Hz. The image data of the frame ofR3 includes combined pixel elements of the frames corresponding to thethree slots of P2, P3, and P4, out of the four slots of the original 240Hz, in a time width of 60 Hz. Thus, a shutter angle (shutter rate) γ ofthe frame of R3 is 270 degrees (7 as expressed by the followingmathematical expression (5).

γ=360*60/240*3=270   (5)

In a case where the image data in the low-frame-rate compatible mode onwhich the mixing processing is performed, which is shown in (b) of FIG.9, is transmitted to the reception side, for example, the encoder 102 bperforms encoding as follows. In other words, the base stream STbcontains encoded image data of image data in a 60-Hz hierarchal layer(see image data of frame (picture) of Q3). Further, the first enhancedstream STe1 contains encoded image data of image data in a 120-Hzhierarchal layer (see image data of frame (picture) of Q1). Further, thesecond enhanced stream Ste2 contains encoded image data of image data ina 240-Hz hierarchal layer (see image data of frames (pictures) of Q2 andQ4).

Note that the example of FIG. 9 shows that the shutter angle (shutterrate) α at imaging as 360 degrees (100%), but another example is alsoconceived similarly. For example, in a case where α=288 degrees,β=288*3=864 degrees, and γ=288*3/4=216 degrees. This applies to not onlythe example of FIG. 9 but also the following examples of FIG. 10 andFIG. 11.

With reference to FIG. 10, another example of the mixing processing willbe described. In. FIG. 10, (a) shows image data in an incompatible modeon which the mixing processing is not performed, the image data having abasic format. This image data is image data obtained when imaging isperformed at a frame frequency of 240 Hz (240 fps) and at a shutterspeed of 1/240 sec. The image data has a configuration in which fourframe (picture) sections of P1, P2, P3, and P4 are repeated. A shutterangle (shutter rate) α of each frame in this case is 360 degrees (100%)(see FIG. 7A).

In FIG. 10, (b) shows image data of 120 Hz in a low-frame-ratecompatible mode on which the mixing processing is performed. The imagedata has a configuration in which two frame sections of S1 and S3 arerepeated. The image data of the frame of S1 is the same as the imagedata of the frame of PI. The frame of S1 has a time width of 120 Hz,which corresponds to a time width including two slots of 240 Hz.

If the image data of the frame of S1 includes pixel elements of the twoslots of P1 and P2, the shutter angle (shutter rate) is 360 degrees(100%). However, since the image data of the frame of S1 includes onlythe pixel element of the slot of P1, the shutter angle (shutter rate) ofthe frame of S1 is 180 degrees (50%).

The image data of the frame of S3 is mixed image data t (P2, P3, P4)obtained by performing filter operation on the image data of the framesof P2, P3, and P4. The frame of S3 has a time width of 120 Hz, whichcorresponds to a time width including two slots of 240 Hz. If the imagedata of the frame of S3 includes the pixel elements of two slots of P3and P4, the shutter angle (shutter rate) is 360 degrees (100%).

However, the image data of the frame of S3 includes the pixel elementsof three slots, i.e., the slot of P2 in addition to the two slots of P3and P4. Thus, the shutter angle (shutter rate) β of the frame of S3 is540 degrees (150%) as expressed by the following mathematical expression(6).

β=360*120/240*3=540   (6)

In FIG. 10, (c) shows image data obtained when the reception sideextracts the image data of the frame of S3 on which the mixingprocessing is performed, and then displays such image data at 60 Hz.Image data of a frame of T3 is for displaying the image data of theframe of S3 at time intervals of 60 Hz. The image data of the frame ofT3 includes combined pixel elements of the frames corresponding to thethree slots of P2, P3, and P4, out of the four slots of the original 240Hz, in a time width of 60 Hz. Thus, a shutter angle (shutter rate) γ ofthe frame of T3 is 270 degrees (75%) as expressed by the followingmathematical expression (7).

γ=360*60/240*3=270   (7)

In a case where the image data in the low-frame-rate compatible mode onwhich the mixing processing is performed, which is shown in (b) of FIG.10, is transmitted to the reception side, for example, the encoder 102 bperforms encoding as follows. In other words, the base stream STbcontains encoded image data of image data in a 60-Hz hierarchal layer(see image data of frame (picture) of S3). Further, the first enhancedstream STe1 contains encoded image data of image data in a 120-Hzhierarchal layer (see image data of frame (picture) of S1). In thiscase, the second enhanced stream Ste2 is not generated.

With reference to FIG. 11, still another example of the mixingprocessing will be described. In FIG. 11, (a) shows image data in anincompatible mode on which the mixing processing is not performed, theimage data having a basic format. This image data is image data obtainedwhen imaging is performed at a frame frequency of 240 Hz (240 fps) andat a shutter speed of 1/240 sec. The image data has a configuration inwhich four frame (picture) sections of P1, P2, P3, and P4 are repeated.A shutter angle (shutter rate) α of each frame in this case is 360degrees (100%) (see FIG. 7A).

In FIG. 11, (b) shows image data of 120 Hz in a low-frame-ratecompatible mode on which first-stage mixing processing is performed.Although detailed description will be omitted, such image data is thesame as the image data shown in (b) of FIG. 10.

In FIG. 11, (c) shows image data of 120 Hz in a low-frame-ratecompatible mode on which second-stage mixing processing is performed.The image data has a configuration in which two frame sections of U1 andU3 are repeated. The image data of the frame of U1 is the same as theimage data of the frame of S1.

The image data of the frame of U3 is mixed image data t (S1, S3)obtained by performing filter operation on the image data the frames ofS1 and S3. The frame of U3 has a time width of 120 Hz, which correspondsto a time width including two slots of 240 Hz. If the image data of theframe of U3 includes the pixel elements of two slots of P3 and P4, theshutter angle (shutter rate) is 360 degrees (100%).

However, the image data of the frame of U3 includes the pixel elementsof four slots, i.e., the slots of P1 and P2 in addition to the two lotsof P3 and P4. Thus, the shutter angle (shutter rate) β of the frame ofU3 is 360*2 degrees (200%) as expressed by the following mathematicalexpression (8).

β=360*120/240*4=360*2   (8)

In FIG. 11, (d) shows image data obtained when the reception sideextracts the image data of the frame of U3 on which the mixingprocessing is performed, and then displays such image data at 60 Hz.Image data of a frame of W3 is for displaying the image data of theframe of U3 at time intervals of 60 Hz. The image data of the frame ofW3 includes combined pixel elements of the frames corresponding to allthe four slots of the original 240 Hz, in a time width of 60 Hz. Thus, ashutter angle (shutter rate) γ of the frame of W3 is 360 degrees (100%)as expressed by the following mathematical expression (9).

γ=360*60/240*4=360   (9)

In a case where the image data in the low-frame-rate compatible mode onwhich the mixing processing is performed, which is shown in (c) of FIG.11, is transmitted to the reception side, for example, the encoder 102 bperforms encoding as follows. In other words, the base stream STbcontains encoded image data of image data in a 60-Hz hierarchal layer(see image data of frame (picture) of U3). Further, the first enhancedstream STe1 contains encoded image data of image data in a 120-Hzhierarchal layer (see image data of frame (picture) of U1). In thiscase, the second enhanced stream Ste2 is not generated.

Transmission of Metadata

As described above, on the transmission side(imaging/production/delivery) of FIG. 2, when the image data having thepredetermined frame frequency on which the mixing processing isperformed is to be packetized and transmitted to the next stage,metadata including information regarding the mixing processing is alsoto be transmitted in association with image data of each frame.

Here, as derived above, metadata is to be transmitted by, for example,inserting the metadata into a payload header of a packet including atleast the top of the image data of each frame (first method).Alternatively, metadata is to be transmitted by using ametadata-dedicated packet associated with a packet including the imagedata of each frame (second method). Note that the metadata transmissionmethod is not limited to the first method and the second method.Hereinafter, details of the first method and the second method will bedescribed.

First Method

The first method is to transmit metadata by inserting the metadata intoa payload header of a packet including at least the top of the imagedata of each frame.

FIG. 12 shows an example of a packet. This is an example standardized as“ST 2022-6 Transport of High Bit Rate Media Signals over IP Networks(HBRMT)”. This standard is for IP transmission of SDI signals. In thestandard, Society of Motion Picture and Television Engineers (SBPTE)prescribe IP packets. In the case of this standard, video and audio dataare mixed and inserted in the payload.

In this standard, an SDI stream (picture data) is sectioned in 1376bytes each, to obtain media payloads. A payload header is added to eachof the media payloads, and an RTP header of 12 bytes is further addedthereto and encapsulated into an RTP packet. In the “SMPTE ST 2022-6”standard, the IP transmission by 3G-SDI for transmitting a 1080p-videoto an uncompressed stream is prescribed. Note that actually an UDPheader is added to the RTP packet, and an IP packet is further addedthereto, thus transmitting the resultant packet as an IP packet.

FIG. 13 shows a structural example (Syntax) of the RTP header. FIG. 14shows the contents (Semantics) of main information in that structuralexample. A version number (V) indicates a version of the RTP, and thecurrent version is 2. A padding bit (P) indicates that the payload ispadded (1) or not padded (0).

A header extension bit (X) indicates that the extension header is added(1) or not added (0). CSRC count (CC) indicates the length of a CSRClist. In a case where the payload is combination of a plurality of mediastreams, an SSRC list of each media stream is stored as a contributingsource (CSRC) list.

A marker bit (M) indicates the occurrence of an important event definedby an RTP profile to be used. The marker bit (M) is used for indicatingthe start, restart, end, or the like of the stream. A payload type (PT)is used for identifying the medium type of payload data and indicates amedia encoding method defined in RFC 3551. For example, the value “98”indicates “ST2022-6”, “New_Value1” newly defined. indicates “ST2110-20”,and “New_Value2” newly defined indicates “metadata”.

A sequence number is an unsigned 16-bit integer value that isincremented by 1 each time the packet is transmitted. In general, theinitial value is set at random. The sequence number is used to detectmissing packets or used for alignment. A time stamp indicates an instantat which the top of the payload data is sampled. The time stamp is usedfor reproduction of media. The value of the time stamp is incrementedfor each packet at transmission of the RTP packets.

A synchronization source (SSRC) identifier an SSRC of a packettransmitter.

FIG. 15 shows a structural example (Syntax) of the payload header. FIG.16 shows the contents (Semantics) of main information in the structuralexample. This payload header is information for specifying thatreproduction of contents to be transmitted by the payload of the packetcan be performed in synchronization with the reception side.

A 4-bit field of “Ext” represents the number of extension words (1 wordin 4 bytes) of the payload header. In a 1-bit field of “F”, “1”indicates that a video format is included, and “0” indicates informationother than a video, such as metadata. In a case where information isother than a video, the values of the following elements, “FRcount”,“R”, “FRAME”, and “FRATE” do not have meanings.

In a 3-bit field of “VSID”, “0” indicates “primary”, and “1” indicates“protect”. An 8-bit field of “FRcount” indicates a value increased foreach video frame. A 2-bit field of “R” indicates reference of a videotimestamp. “00” indicates “not locked”, “01” indicates “UTC”, and “10”indicates “private reference”.

A 2-bit field of “S” indicates that the payload is scrambled or not.“00” indicates that scrambling is not performed. A 3-bit field of “FEC”indicates the type of an error-correcting code to be used. “000”indicates “none”, “001” indicates “column”, and “010” indicates“row&column”.

A 4-bit field of “CF” indicates a clock frequency of the video signal.“0×1” indicates 27 MHz. A 4-bit field of “MAP” indicates the type of anSDI stream. An 8-bit field of “FRAME” specifies a combination of ascanning method for the video signal, the number of pixels, and thelike.

An 8-bit field of “FRATE” indicates a frame frequency of the videosignal. A 4-bit field of “SAMPLE” indicates the chroma samplingstructure of the video signal. A 32-bit field of “Video timestamp” ispresent when the value of “CF” is larger than 0, and is the time stampfor video signal synchronization between transmission and reception. Theaccuracy thereof is indicated by the value specified by the clockfrequency of the video signal.

In such a payload header, when the value of “Ext” is larger than 0, thenumber of fields of “Header extension” is the number of words indicatedby the value of “Ext”. In this field, information of “Extension type”indicating an extension type is also included. In the first method,“shutter_blendng ( )”, which is metadata including information regardingmixing processing is inserted into the field of “Header extension”.

FIG. 17 shows a structural example (Syntax) of “shutter blending ( )”.FIG. 18 shows the contents (Semantics) of main information in thatstructural example. An 8-bit field of “metadata type” indicates ametadata type. In a case of “0×0A”, an extension region is defined as inthis syntax/semantics.

An 8-bit field of “shutter_blending_length” represents a byte size fromthe next element. An 8-bit field of “video_stream_id” indicates a targetvideo stream ID and is used only when used outside of the video packet.

A 4-bit field of “reference_shutter_speed_code” is a code value of areference shutter speed (camera shutter speed mainly at capturing). Forexample, “0×1” indicates 1/24 sec, “0×2” indicates 1/25 sec, “0×3”indicates 1/30 sec, “0×4” indicates 1/50 sec, “0×5” indicates 1/60 sec,“0×6” indicates 1/100 sec, “0×7 ” indicates 1/120 sec, “0×8” indicates1/180 sec, “0×9” indicates 1/200 sec, and “0×A” indicates 1/240 sec.

A 4-bit field of “number_of_blend_stages” indicates the number of stagesof mixing processing. The value thereof is 1 or more. The followingelements repeatedly appear in number corresponding to the number ofstages.

A 4-bit field of “reference_framerate_code” is a code value of areference frame rate (=frame rate of picture as mixing processingtarget). For example, “0×1” indicates 24 fps, “0×2” indicates 25 fps,“0×3” indicates 30 fps, “0×4” indicates 50 fps, “0×5” indicates 60 fps,“0×6” indicates 100 fps, “0×7” indicates 120 fps, “0×8” indicates 200fps, and “0×9” indicates 240 fps.

A 4-bit field of “current_framerate_code” is a code value of the currentframe rate (=frame rate of picture after mixing processing). Forexample, “0×1” indicates 24 fps, “0×2” indicates 25 fps, “0×3” indicates30 fps, “0×4” indicates 50 fps, “0×5” indicates 60 fps, “0×6” indicates100 fps, “0×7” indicates 120 fps, “0×8” indicates 200 fps, and “0×9”indicates 240 fps.

A 1-bit field of “blending_flag” is a blend flag indicating that themixing processing is performed or not. “1” indicates that the mixingprocessing is performed, and “0” indicates that the mixing processing isnot performed. When the blend flag is “1”, the following elements arepresent.

A 2-bit field of “blend_targets_code” indicates a mixing processingtarget. It indicates that a picture to be mixed with the current pictureat the reference frame rate is any of a previous picture, a subsequentpicture, or both of a previous picture and a subsequent picture withrespect to the current picture. For example, “10” indicates “previouspicture”, “01” indicates “subsequent picture”, and “11” indicates “bothof previous and subsequent pictures”.

A 4-bit field of “blend_coefficients_code” is a code value indicating ablend ratio (filter operation coefficient ratio at mixing). A value ofthe larger ratio is set as a weighting coefficient for the currentpicture, and a value of the smaller ratio is set as a weightingcoefficient for previous and subsequent mixing target pictures. Forexample, “0×1” indicates “1:1”, “0×2” indicates “2:1”, “0×3” indicates“4:1”, and “0×4” indicates “1:2:1”.

Specific Example of Metadata

First, description will be given on a specific example of metadata in acase where the image data in the low-frame-rate compatible mode on whichthe mixing processing is performed, which is shown in (b) of FIG. 9, istransmitted to the reception side. FIG. 19A shows a specific example ofmetadata (metadata A) transmitted in association with the image data ofeach of the frames of Q1, Q2, and Q4. In this case, the referenceshutter speed is 1/240 sec, the reference frame rate is 240 fps, thecurrent frame rate is 240 fps, and the blend flag is “0”.

In this case, on the reception side, it is found from the referenceshutter speed and the reference frame rate that the original shutterangle is 360 degrees (100%). Further, since the current frame rate issame as the reference frame rate, it is found that the shutter angle ofthat frame is 360 degrees (100%). Further, it is found from the blendflag that the mixing processing is not performed on the image data ofthose frames.

FIG. 19B shows a specific example of metadata (metadata A) transmittedin association with the image data of the frame of Q3. In this case, thereference shutter speed is 1/240 sec, the reference frame rate is 240fps, the current frame rate is 240 fps, the blend flag is “1”, mixingprocessing targets are both of a previous picture and a subsequentpicture, and the blend. ratio is 1:2:1.

In this case, on the reception side, it is found from the referenceshutter speed and the reference frame rate that the original shutterangle is 360 degrees (100%). Further, it is found from the mixingprocessing targets that the image data of that frame is data obtained bymixing three pictures at the ratio of 1:2:1 by using both of theprevious picture and the subsequent picture as mixing processingtargets. By the mixing processing, the shutter angle is converted into360*3=1080 degrees (300%). Since the current frame rate is the same asthe reference frame rate, it is found that the shutter angle of thatframe is 360 degrees (100%).

Next, description will be given on a specific example of metadata in acase where the image data in the low-frame-rate compatible mode on whichthe mixing processing is performed, which is shown in (b) of FIG. 10, istransmitted to the reception side. FIG. 20A shows a specific example ofmetadata (metadata A) transmitted in association with the image data ofthe frame of S1. In this case, the reference shutter speed is 1/240 sec,the reference frame rate is 240 fps, the current frame rate is 120 fps,and the blend flag is “0”.

In this case, on the reception side, it is found from the referenceshutter speed and the reference frame rate that the original shutterangle is 360 degrees (100%). Further, since a time axis of the currentframe rate is twice a time axis of the reference frame rate, it is foundthat the shutter angle of that frame is 180 degrees (50%). Further, itis found from the blend flag that the mixing processing is not performedon the image data of that frame.

FIG. 20B shows a specific example of metadata (metadata A) transmittedin association with the image data of the frame of S3. In this case, thereference shutter speed is 1/240 sec, the reference frame rate is 240fps, the current frame rate is 120 fps, the blend flag is “1”, mixingprocessing targets are both of a previous picture and a subsequentpicture, and the blend ratio is 1:2:1.

In this case, on the reception side, it is found from the referenceshutter speed and the reference frame rate that the original shutterangle is 360 degrees (100%). Further, it is found from the mixingprocessing targets that the image data of that frame is data obtained bymixing three pictures at the ratio of 1:2:1 by using both of theprevious picture and the subsequent picture as mixing processingtargets. By the mixing processing, the shutter angle is converted into360*3=1080 degrees (300%). Since the time axis of the current frame rateis twice the time axis of the reference frame rate, it is found that theshutter angle of that frame is 540 degrees (150%).

Next, description will he given on a specific example of metadata in acase where the image data in the low-frame-rate compatible mode on whichtwo-stage mixing processing is performed, which is shown in (c) of FIG.11, is transmitted to the reception side. (a) and (b) of FIG. 21 showspecific examples of the metadata (metadata A) transmitted in associatedwith the image data of the respective frames of S1 and S3 in (b) of FIG.11. Although detailed description will be omitted, the description onFIGS. 20A and 20B apply to such metadata (metadata A).

In FIG. 21, (c) shows a specific example of metadata (metadata B)transmitted in association with the image data of the frame of U1. Suchmetadata (metadata B) contains information regarding first-stage mixingprocessing shown in (a) of FIG. 21 and also information regardingsecond-stage mixing processing. Regarding the second-stage mixingprocessing, the reference frame rate is 120 fps, the current frame rateis 120 fps, and the blend flag is “0”.

In this case, on the reception side, since the current frame rate is thesame as the reference frame rate, it is found that the shutter angle ofthat frame is 360 degrees (100%) like the shutter angle of the frame ofS1. Further, it is found from the blend flag that the mixing processingis not performed on the image data of that frame.

In FIG. 21, (d) shows a specific example of metadata (metadata B)transmitted in association with the image data of the frame of U3. Suchmetadata (metadata B) contains information regarding first-stage mixingprocessing shown in (b) of FIG. 21 and also information regardingsecond-stage mixing processing. Regarding the second-stage mixingprocessing, the reference frame rate is 120 fps, the current frame rateis 120 fps, the blend flag is “1”, the mixing processing target is aprevious picture, and the blend ratio is 4:1.

In this case, it is found from the mixing processing target that theimage data of that frame is data obtained by mixing two pictures at theratio of 4:1 by using the previous picture as a mixing processingtarget. By the mixing processing, it is found that the shutter angle ofthat frame is 540+180=720 degrees (200%).

FIG. 22 shows an example in which pictures are transmitted in aplurality of packets (media packets) through the RTP transmission. Thisexample shows a state where a picture is divided into two RTP packets,but the present technology is not limited thereto. For example, aplurality of lines of pictures may be transmitted in one packet, and onepicture may be transmitted in a plurality of packets. Further, thisexample shows that metadata is inserted into the payload header of allof the packets, but it is sufficient if metadata is inserted into thepayload header of a packet including at least the top of image data ofeach frame. Note that only the video is illustrated in this example, butactually the ST2022-6 permits mixture of video and audio data.

Second Method

The second method is to transmit metadata by using a metadata-dedicatedpacket associated with a packet including image data of each frame.

FIG. 23 shows an example in which pictures are transmitted in aplurality of packets (media packets) through the RTP transmission, likeFIG. 22. Note that, for the purpose of simplifying the drawings, theillustration of a UDP header and an OP header is omitted in thisexample.

In the example of FIG. 23, metadata packets are present in addition tothe media packets. In the second method, the metadata packet is newlydefined, and using the metadata packet, metadata including informationregarding mixing processing is transmitted in association with eachframe. In this case, a target video packet of the metadata is linked by“video_stream_id”. Further, target pictures are synchronized by“Video_timestamp”.

FIG. 24 shows a structural example (Syntax) of the payload header inthis case. In the payload header, “Video_stream_id” is newly definedusing a reserve region, for example, “EMT-RESERVE”. The“video_stream_id” has a value uniquely determined in a programdistribution, and can be caused to cooperate with another distributionpacket (see FIG. 23).

Note that, although detailed description will be omitted, the structureother than the payload header is similar to the structural example shownin FIG. 15. Note that, in this case, the metadata is not inserted intothe payload header. Note that “Video_timestamp” is present in thepayload header.

The metadata is delivered in the payload of an RTP packet different fromthe video. The metadata can be synchronized and associated with eachpicture of a target video by “video_stream_id” and “Video_timestamp”. Inthis case, “New_value2” is entered in the payload type (PT) of the RTPheader, and “0” is entered in the “F” of the payload header, whichindicates that the payload is not a video. The format data of“shutter_blending ( )” is inserted into the payload region as it is andthen transmitted.

FIG. 25 shows a structural example (Syntax) of a payload header and apayload of the metadata packet. The payload header region includes a32-bit field of “metadata start word” that is identification informationof a metadata packet, and a 32-bit field of “Video_timestamp”. Then,“shutter_blending ( )” (see FIG. 17) that is metadata includinginformation regarding mixing processing is inserted into the payloadregion. The “shutter_blending ( )” includes “video_stream_id”.

As described above, on the transmission side(imaging/production/delivery) of the transmission/reception system 10shown in FIGS. 2 and 3, when the image data having a predetermined framefrequency on which the mixing processing is performed is packetized andtransmitted to the next stage, metadata including information regardingmixing processing is also transmitted in association with image data ofeach frame. Thus, the image data on which the mixing processing isperformed can be favorably handled on the reception side, for example,at the transmission of materials of the image data.

2. Modified Example

Note that, in the embodiment described above, the packet containingimage data (video data) has been described by using a packet of the “ST2022-6” standard as an example. However, the present technology issimilarly applicable to a case where the packet containing image data isanother packet, for example, a packet of the “ST 2110-20” standard. In acase of the packet of the “ST 2110-20” standard, only a video isinserted into the payload.

Further, a suitable embodiment of the present disclosure has beendescribed in details with reference to the accompanying drawings, whilethe technical range of the present disclosure is not limited to suchexamples. It is apparent that a person having ordinary skill in thetechnical field of the present disclosure could arrive at variousalterations or modifications within the technical ideas described in thescope of claims, and it should be understood that they will naturallycome under the technical scope of the present disclosure.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art on the basis of the description of thisspecification.

Further, the present technology can have the following configurations.

-   (1) A transmission apparatus, including    -   a transmission unit that        -   transmits a packet including divided image data as payload            data, the divided image data being obtained by dividing            image data having a predetermined frame frequency into a            predetermined number of frames,        -   the image data having the predetermined frame frequency            being subjected to mixing processing for each frame, image            data of a previous frame and/or a subsequent frame being            selectively used in the mixing processing, and        -   further transmits metadata including information regarding            the mixing processing in association with image data or each            frame.-   (2) The transmission apparatus according to (1), in which

the transmission unit inserts the metadata into a payload header of thepacket including at least a top of the image data of each frame andtransmits the metadata.

-   (3) The transmission apparatus according to (1), in which

the transmission unit transmits the metadata in a metadata-dedicatedpacket associated with the packet including the image data of eachframe.

-   (4) The transmission apparatus according to any one of (1) to (3),    in which

the information regarding the mixing processing includes informationindicating whether image data of a corresponding frame is subjected tomixing processing or not.

-   (5) The transmission apparatus according to any one of (1) to (4),    in which

the information regarding the mixing processing includes information ofa camera shutter speed at capturing.

-   (6) The transmission apparatus according to any one of (1) to (5),    in which

the information regarding the mixing processing includes information ofa frame rate of a mixing processing target picture.

-   (7) The transmission apparatus according to any one of (1) to (6),    in which

the information regarding the mixing processing includes information ofa frame rate obtained after the mixing processing.

-   (8) The transmission apparatus according to any one of (1) to (7),    in which

the information regarding the mixing processing includes informationindicating a mixing processing target picture.

-   (9) The transmission apparatus according to any one of (1) to (8),    in which

the information regarding the mixing processing includes informationindicating a filter operation coefficient ratio at mixing.

-   (10) The transmission apparatus according to any one of (1) to (9),    in which

the mixing processing includes a predetermined number of stages of themixing processing.

-   (11) The transmission apparatus according to any one of (1) to (10),    in which

the packet conforms to a format prescribed by a standard regarding videosignal transmission using an Internet protocol (IP) network.

-   (12) The transmission apparatus according to (11), in which

the standard is SMPTE ST2022-6.

-   (13) The transmission apparatus according to (11), in which

the standard is SMPTE ST2110-20.

-   (14) The transmission apparatus according to any one of (1) to (13),    further including

a mixing processing unit that performs the mixing processing.

-   (15) A transmission method, including

transmitting a packet including divided image data as payload data, thedivided image data being obtained by dividing image data having apredetermined frame frequency into a predetermined number of frames,

the image data having the predetermined frame frequency being subjectedto mixing processing for each frame, image data of a previous frameand/or a subsequent frame being selectively used in the mixingprocessing; and

transmitting metadata including information regarding the mixingprocessing in association with image data of each frame.

-   (16) An encoding apparatus, including:

a reception unit that

-   -   receives a packet including divided image data as payload data,        the divided image data being obtained by dividing image data        having a predetermined frame frequency into a predetermined        number of frames,    -   the image date having the predetermined frame frequency being        subjected to mixing processing for each frame, image data of a        previous frame and/or a subsequent frame being selectively used        in the mixing processing, and    -   further receives metadata including information regarding the        mixing processing, the metadata being associated with image data        of each frame,    -   the information regarding the mixing processing including        information indicating whether image data of a corresponding        frame is subjected to mixing processing or not; and

an encoding unit that, on the basis of the information regarding themixing processing, encodes, among the image data having thepredetermined frame frequency, image data of a frame subjected to themixing processing as image data of a base layer and encodes, among theimage data having the predetermined frame frequency, image data of aframe not subjected to the mixing processing as image data of anenhanced layer.

-   (17) An encoding method, including:

receiving a packet including divided image data as payload data, thedivided image data being obtained by dividing image data having apredetermined frame frequency into a predetermined number of frames,

the image data having the predetermined frame frequency being subjectedto mixing processing for each frame, image data of a previous frameand/or a subsequent frame being selectively used in the mixingprocessing;

receiving metadata including information regarding the mixingprocessing, the metadata being associated with image data of each frame,

the information regarding the mixing processing including informationindicating whether image data of a corresponding frame is subjected tomixing processing or not; and

encoding, among the image data having the predetermined frame frequency,image data of a frame subjected to the mixing processing as image dataof a base layer and encoding, among the image data having thepredetermined frame frequency, image data of a frame not subjected tothe mixing processing as image data of an enhanced layer, on the basisof the information regarding the mixing processing.

-   (18) A reception apparatus, including:

a reception unit that

-   -   receives a packet including divided image data as payload data,        the divided image data being obtained by dividing image data        having a predetermined frame frequency into a predetermined        number of frames,    -   the image data having the predetermined frame frequency being        subjected to mixing processing for each frame, image data of a        previous frame and/or a subsequent frame being selectively used        in the mixing processing, and    -   further receives metadata including information regarding the        mixing processing, the metadata being associated with image data        of each frame; and

a processing unit that performs inverse mixing processing on the imagedata having the predetermined frame frequency on the basis of theinformation regarding the mixing processing, and acquires image data fordisplay.

-   (19) A reception method, including:

receiving a packet including divided image data as payload data, thedivided image data being obtained by dividing image data having apredetermined frame frequency into a predetermined number of frames,

the image data having the predetermined frame frequency being subjectedto mixing processing for each frame, image data of a previous frameand/or a subsequent frame being selectively used in the mixingprocessing;

receiving metadata including information regarding the mixingprocessing, the metadata being associated with image data of each frame;and

performing inverse mixing processing on the image data having thepredetermined frame frequency on the basis of the information regardingthe mixing processing, and acquiring image data for display.

What is claimed is:
 1. A transmission apparatus, comprising atransmission unit that transmits a packet including divided image dataas payload data, the divided image data being obtained by dividing imagedata having a predetermined frame frequency into a predetermined numberof frames, the image data having the predetermined frame frequency beingsubjected to mixing processing for each frame, image data of a previousframe and/or a subsequent frame being selectively used in the mixingprocessing, and further transmits metadata including informationregarding the mixing processing in association with image data of eachframe.
 2. The transmission apparatus according to claim 1, wherein thetransmission unit inserts the metadata into a payload header of thepacket including at least a top of the image data of each frame andtransmits the metadata.
 3. The transmission apparatus according to claim1, wherein the transmission unit transmits the metadata in ametadata-dedicated packet associated with the packet including the imagedata of each frame.
 4. The transmission apparatus according to claim 1,wherein. the information regarding the mixing processing includesinformation indicating whether image data of a corresponding frame issubjected to mixing processing or not.
 5. The transmission apparatusaccording to claim 1, wherein the information regarding the mixingprocessing includes information of a camera shutter speed at capturing.6. The transmission apparatus according to claim 1, wherein theinformation regarding the mixing processing includes information of aframe rate of a mixing processing target picture.
 7. The transmissionapparatus according to claim 1, wherein the information regarding themixing processing includes information of a frame rate obtained afterthe mixing processing.
 8. The transmission apparatus according to claim1, wherein the information regarding the mixing processing includesinformation indicating a mixing processing target picture.
 9. Thetransmission apparatus according to claim 1, wherein the informationregarding the mixing processing includes information indicating a filteroperation coefficient ratio at mixing.
 10. The transmission apparatusaccording to claim 1, wherein the mixing processing includes apredetermined number of stages of the mixing processing.
 11. Thetransmission apparatus according to claim 1, wherein the packet conformsto a format prescribed by a standard regarding video signal transmissionusing an internet protocol (IP) network.
 12. The transmission apparatusaccording to claim 11, wherein the standard is SMPTE ST2022-6.
 13. Thetransmission apparatus according to claim 11, wherein the standard isSMPTE ST2110-20.
 14. The transmission apparatus according to claim 1,further comprising a mixing processing unit that performs the mixingprocessing.
 15. A transmission method, comprising transmitting a packetincluding divided image data as payload data, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames, the image data havingthe predetermined frame frequency being subjected to mixing processingfor each frame, image data of a previous frame and/or a subsequent framebeing selectively used in the mixing processing; and transmittingmetadata including information regarding the mixing processing inassociation with image data of each frame.
 16. An encoding apparatus,comprising: a reception unit that receives a packet including dividedimage data as payload data, the divided image data being obtained bydividing image data having a predetermined frame frequency into apredetermined number of frames, the image data having the predeterminedframe frequency being subjected to mixing processing for each frame,image data of a previous frame and/or a subsequent frame beingselectively used in the mixing processing, and further receives metadataincluding information regarding the mixing processing, the metadatabeing associated with image data of each frame, the informationregarding the mixing processing including information indicating whetherimage data of a corresponding frame is subjected to mixing processing ornot; and an encoding unit that, on a basis of the information regardingthe mixing processing, encodes, among the image data having thepredetermined frame frequency, image data of a frame subjected to themixing processing as image data of a base layer and encodes, among theimage data having the predetermined frame frequency, image data of aframe not subjected to the mixing processing as image data of anenhanced layer.
 17. An encoding method, comprising: receiving a packetincluding divided image data as payload data, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames, the image data havingthe predetermined frame frequency being subjected to mixing processingfor each frame, image data of a previous frame and/or a subsequent framebeing selectively used in the mixing processing; receiving metadataincluding information regarding the mixing processing, the metadatabeing associated with image data of each frame, the informationregarding the mixing processing including information indicating whetherimage data of a corresponding frame is subjected to mixing processing ornot; and encoding, among the image data having the predetermined framefrequency, image data of a frame subjected to the mixing processing asimage data of a base layer and encoding, among the image data having thepredetermined frame frequency, image data of a frame not subjected tothe mixing processing as image data of an enhanced layer, on a basis ofthe information regarding the mixing processing.
 18. A receptionapparatus, comprising: a reception unit that receives a packet includingdivided image data as payload data, the divided image data beingobtained by dividing image data having a predetermined frame frequencyinto a predetermined number of frames, the image data having thepredetermined frame frequency being subjected to mixing processing foreach frame, image data of a previous frame and/or a subsequent framebeing selectively used in the mixing processing, and further receivesmetadata including information regarding the mixing processing, themetadata being associated with image data of each frame; and aprocessing unit that performs inverse mixing processing on the imagedata having the predetermined frame frequency on a basis of theinformation regarding the mixing processing, and acquires image data fordisplay.
 19. A reception method, comprising: receiving a packetincluding divided image data as payload data, the divided image databeing obtained by dividing image data having a predetermined framefrequency into a predetermined number of frames, the image data havingthe predetermined frame frequency being subjected to mixing processingfor each frame, image data of a previous frame and/or a subsequent framebeing selectively used in the mixing processing; receiving metadataincluding information regarding the mixing processing, the metadatabeing associated with image data of each frame; and performing inversemixing processing on the image data having the predetermined framefrequency on a basis of the information regarding the mixing processing,and acquiring image data for display.